The present disclosure relates to a pressed-connection arrangement having a connection piece. The connection piece may be made of a cold-workable material, which is constructed on a fitting or a valve and into which a pipe end can be pushed. The connection piece has a ring-shaped receiving device in which a metallic cutting ring and a sealing ring are held.
From German Patent Document DE 297 21 760, a pressed connection between a fitting and a metal pipe end is known. A receiving device for a sealing ring and a spaced receiving device for a cutting ring is provided on the fitting. A pipe end is pushed into the connection piece, and a radial pressing-together is then carried out in order to establish a sealed-off connection, the cutting ring providing a mechanical fixing of the pipe end. The providing of a receiving device for the sealing ring and of a receiving device for the cutting ring requires comparatively high expenditures. It is difficult to produce the connection piece by a forming method because, when the second receiving device is produced, there is the risk that the already produced first receiving device will be deformed again. In practice, corresponding connection pieces are therefore cast and subsequently finished.
From U.S. Patent Document U.S. Pat. No. 5,108,134, another pressed connection is known, in which a cutting ring and a sealing ring are arranged adjacent to one another on a connection piece. There is the risk that, during the pressing-together of the connection, the sealing ring may be damaged and its tightness can therefore not be guaranteed. In addition, the cutting ring is situated on the side facing the pipe end in the hydraulically guided area, so that a contamination of the piping system by the cutting ring cannot be excluded.
The present disclosure is related to a pressed-connection arrangement which ensures a durable sealing-off while its construction is simple.
The present disclosure includes a pressed connection arrangement including a pipe end, and a connection piece configured to receive the pipe end. The connection piece includes a ring-shaped receiving device including a cutting ring and a sealing ring.
Further, according to the present disclosure, a separating ring is provided between the sealing ring and the cutting ring, by which separating ring the cutting ring is held at a distance from the sealing ring. As a result, only a single ring-shaped receiving device has to be shaped out at the connection piece, in which receiving device the sealing ring, the separating ring and the cutting ring will then be held. The arrangement of a separating ring between the sealing ring and the cutting ring represents a simplification in comparison to the separate construction of receiving devices. By the separating ring, it is ensured that, during the pressing-together, the sealing ring is not damaged by the cutting ring, and a durable sealing-off can therefore be ensured.
According to an embodiment of the present disclosure; the sealing ring, the separating ring and the cutting ring are held in a prefixed manner as a preassembled unit in the essentially U-shaped receiving device before a pressing-together. In addition, the receiving device may have two inward-extending legs and the preassembled unit is thus held in a secured manner in the axial direction and cannot be lost during transport. Furthermore, the arrangement of the individual components cannot accidentally be confused.
The connection piece may be made of metal and produced by forming. A corresponding fitting can thereby be produced from a pipe section, in which case the receiving device can be produced by widening the pipe section. As a result, large diameters of over, for example, 50 mm can also be produced at reasonable cost. For the forming, presses and other tools known per se can be used. This simplifies the production of the connection piece which then no longer has to be produced from cast material with a subsequent surface finishing.
According to another embodiment of the present disclosure, the cutting ring has several cutting teeth which are arranged on a side facing the pipe end and, during the pressing-together, dig into the material of the pipe end. The cutting ring thereby offers a protection against a pulling-out of the pipe, in that the cutting teeth arranged in an inclined manner with respect to a radial direction can provide a particularly good securing of the pressed-connection arrangement. In this case, the cutting ring can be supported on the opposite side of the cutting teeth on a side wall of the receiving device, so that a pulling movement of the pipe can be diminished or absorbed by the connection piece.
The sealing ring can be held in the receiving device on a side facing the pipe end. As a result, the separating ring and the cutting ring are arranged on a side of the receiving device facing away from liquid, and the pipe end or piping system cannot be contaminated.
On its exterior side facing away from the pipe end, the separating ring has a rounded edge projecting to the sealing ring. The separating ring therefore has a set-back receiving device below the rounded edge, in which receiving device the sealing ring can be inserted during the pressing-together. The reason is that, as a result of compression of the sealing ring in the radial direction, its axial dimension becomes larger and the separating ring offers a space to the sealing ring, into which the latter can be pressed. In this case, the separating ring may also form-lockingly rest against the sealing ring and the cutting ring in the axial direction.
For an easy mounting, the separating ring is constructed to be closed in a surrounding manner and includes an elastic material, such as a plastic material, and can be inserted into the receiving device of the connection piece by a slight elastic deformation.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.